Summary: | 碩士 === 輔仁大學 === 資訊工程學系 === 87 === Orthography halftoning is one of the old digital halftoning algorithms. It replaces each pixel in a continuos-tone image with an M by N font. The advantage of orthography algorithm is that when we need to scale up a continuous-tone image before applying halftoning algorithm to the image, orthography algorithm can do both things at the same time, which shortens the processing time considerably. But orthography halftoning algorithm does possess disadvantages. Because orthography algorithm uses only one font to reproduce one gray level, the textures, created from a uniform area, exhibit structure or fixed pattern. It is also common to see some dramatic texture in the halftoned image depending on selected fonts. In this paper, we propose an algorithm to solve these problems. The algorithm uses multiple fonts, which can reproduce the same gray level, to reproduce one gray level. Those fonts are created at run-time for each pixel in the image by putting desired dots into the font randomly.
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